Guard for door-locks



C. M. HATCHER.

GUARD FOR DOOR LOCKS.

APPLICATION men AUG-I8. I919.

Patenfed Feb. 8, 1921.

UNITED STATES I PATENT OFFICE.

GUARD FOR DOOR-LOCKS.

Application filed August 18, 1919.

To all whom 2'2? m a-g concern:

Be it known that I, CHARLES M. HATOHER, a citizen of the United States,residing at Oakland, in the county of Alameda and State of California,have invented certain new and useful Improvements in Guards forDoor-Locks, of which the following is a specification.

This invention relates to improvements in guards for door locks and moreparticularly to a device for preventing the removal of the key therefromor its being turned from the outside.

The principal object of the invention is to provide a simple andeffective guard for accomplishing the results above outlined and onewhich is readily attached to the door and is applicable to all forms oflock employing having a key with a ringed end.

With these and other objects in view the invention consists of certainnovel features of form and structure herein illustrated and morespecifically pointed out in the appended claims.

Reference being had to the drawing formin a part of the specification:

igure 1 is a view in perspective of a door.

Fig. 2 is a view in front elevation of one member of my device.

Fig. 3 is a view in front elevation of the companion piece.

Fig. 4 is a view in section on the line 4-4 Fig. 1.

Referring to corresponding parts in the several views by the samenumerals of reference, 1 denotes a door having the usual type of mortiselock 2, the latch 3 of which is operated by turning a knob at, while thebolt 5 is operated by a key 6.

On the surfaces of the door are attached escutcheon plates 7 having anopening 8 for the key, and an opening for the shank 9 of the knob. Theabove mentioned parts are of the usual construction and require nodetailed description.

The device which comprises my invention is denoted generallyby 10 andcomprises two pieces 11 and 12 which are slidable one in the other. Theouter member 11 comprises a rectangular plate 13 having its side edgesbent back on itself as shown at 14 to form grooves for slidably holdingthe other plate. Plate 13 has an elongated opening 15 which is adaptedto embrace the shank 9 and on its lower end has an ofiset Specificationof Letters Patent.

Patented Feb. 8, 1921.

Serial No. 318,398.

tongue 16 which engages the opening in the key 6. On the upper end ofthis plate there is provided a curved lip 17 which serves as a handlefor moving the plate.

The inner member 12 comprises a rectangular plate 16 having its sidesfolded back as shown at 22 to form smooth edges for engagement with thegrooves formed on plate 13. In the center of plate 16 there is formed acircular opening 17 the diameter of which just admits the knob shank 9.Adjacent the lower end of the plate there is cut an elongated slot 18,the width of which is just suiiicient to allow the key stem to turntherein, and the length of which permits the ring of the key to bepassed therethrough. The upper end of this plate has an extension 19which projects above the escutcheon plate 7 and has a hole 20 throughwhich is passed a screw 21 for attaching the plate to the door.

The guard is attached to the inside of the door with the knob extendingthrough openings 15 and 17. wThus attached the member 11 may be moved upand down on member 12 within the limits of opening 15. The key is placedin the lock by first inserting the ring end through slot 18 from theside adjacent the door. This is necessary as the shoulder on the keyadjacent the bit will not ordinarily pass through the slot. The key bitis then entered into the lock and turned until the bolt 5 is extended.The ring of the key is turned until horizontal or partly so and then theplate 11 pushed downwardly to cause the finger 16 to enter the openingin the keyring.

Now if the door is closed it will be apparent that to open it the boltmust be retracted which can only be done by turning key 6 or by forcingit out and using another or a skeleton key. But the key cannot be turnedfrom the appointed side of the door, due to the tongue 16 extendingthrough the opening in the key. This prevents the bolt from beingretracted and furthermore prevents the key from being turned so that itmay be pushed out of the key hole and a skeleton key used. Furthermoreplate 11" cannot be lifted by a tool inserted through the keyhole as theinner plate prevents the possibility of the tool securing an effectivehold on the plate.

I claim as new and wish to cover by Letters patent 1. A device of thecharacter described comprising in combination with a door lock having anescutcheon plate, a key and a shanked knob, a plate having an openingfor said knob shank and a slot for said key, a tongue on said plateextending past 3 the top of said escutcheon plate, means for at tachingsaid tongue to the door, a member slidable on said plate and having aslot embracing said knob shank, a tongue on the' lower end of saidmember for engaging said key to prevent turning thereof.

2. A device of the character described comprising in combination with adoor lock having a key and a shanked knob, a plate having an opening forsaid knob shank and a slot for said key, a member slidably mounted onsaid plate and having a slot embracing said knob shank, and a tongueextending from the lower end of said member to engage said key andprevent the turning thereof.

'3. A device of the character described comprising in combination with adoor lock having a key and a shanked knob, a plate having one endrigidly held with respect to said door, said'plate having an opening forsaid knob shank and a slot for said key, a member slidably mounted onsaid plate and having a slot embracing said knob shank, and a tongueextending from the lower end of said member to engage said key andprevent the turning thereof.

In testimony whereof I afiix my si nature.

CHARLES M. HATC ER.

